Myeloma analogs constructed by somatic cell hybridization will be selected for important characteristics that will enable them to be used for the routine production of human monoclonal antibodies. These characteristics include the easy growth and high cloning efficiency of the primary cell line, high fusion efficiency, easy growth, and high cloning efficiency of the subsequent hybrids and continuous and stable secretion of antibody by these hybrids. New cell lines will be constructed if the presently available cell lines do not meet the standards set by the laboratory. In addition, myeloma analogs will be selected for ouabain-resistant mutants for fusion with other cell lines to construct new myeloma analogs or for fusion with transformed B lymphocytes secreting antibody. Myeloma analogs meeting the above criteria will be further selected for nonsecreting variants utilizing well-established methods. In order to obtain antibody secreting hybrids or predetermined specificity, methods will be developed to select, activate, and expand populations of B cells for fusion and/or transformation with EBV and subsequent fusion with myeloma analogs. These experiments will start with a system utilizing soluble antigen (tetanus toxoid) and proceed to in vitro secondary immunization utilizing malignant cells or soluble antigen bound to cell surface membranes. The influence of populations of lymphoid cells which may affect the degree of in vitro immunization will be studied. The conditions under which these immunizations are best obtained will be determined. The final stage will involve the production of human monoclonal antibodies to colon carcinoma, melanoma, and acute myelogenous leukemia. (2)